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    <link rel="stylesheet" href="measure.css">
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    <title>Measure example</title>
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        <a class="navbar-brand" href="./"><img src="./resources/logo-70x70.png">&nbsp;OpenLayers 3 Examples</a>
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    </header>

    <div class="container-fluid">

      <div class="row-fluid">
  <div class="span12">
    <div id="map" class="map"></div>
  </div>
</div>
<form class="form-inline">
  <label>Geometry type &nbsp;</label>
    <select id="type">
      <option value="length">Length</option>
      <option value="area">Area</option>
    </select>
    <label class="checkbox"><input type="checkbox" id="geodesic"/>use geodesic measures</label>
</form>


      <div class="row-fluid">
        <div class="span12">
          <h4 id="title">Measure example</h4>
          <p id="shortdesc">Example of using the ol.interaction.Draw interaction for creating simple measuring application.</p>
          <div id="docs"><p><i>NOTE: If use geodesic measures is not checked, measure is done in simple way on projected plane. Earth curvature is not taken into account</i></p>
</div>
          <div id="tags">draw, edit, measure, vector</div>
          <div id="api-links">Related API documentation: <ul class="inline"><li><a href="../apidoc/ol.Map.html" title="API documentation for ol.Map">ol.Map</a></li>,<li><a href="../apidoc/ol.Observable.html" title="API documentation for ol.Observable">ol.Observable</a></li>,<li><a href="../apidoc/ol.Overlay.html" title="API documentation for ol.Overlay">ol.Overlay</a></li>,<li><a href="../apidoc/ol.Sphere.html" title="API documentation for ol.Sphere">ol.Sphere</a></li>,<li><a href="../apidoc/ol.View.html" title="API documentation for ol.View">ol.View</a></li>,<li><a href="../apidoc/ol.geom.LineString.html" title="API documentation for ol.geom.LineString">ol.geom.LineString</a></li>,<li><a href="../apidoc/ol.geom.Polygon.html" title="API documentation for ol.geom.Polygon">ol.geom.Polygon</a></li>,<li><a href="../apidoc/ol.interaction.Draw.html" title="API documentation for ol.interaction.Draw">ol.interaction.Draw</a></li>,<li><a href="../apidoc/ol.layer.Tile.html" title="API documentation for ol.layer.Tile">ol.layer.Tile</a></li>,<li><a href="../apidoc/ol.layer.Vector.html" title="API documentation for ol.layer.Vector">ol.layer.Vector</a></li>,<li><a href="../apidoc/ol.proj.html" title="API documentation for ol.proj">ol.proj</a></li>,<li><a href="../apidoc/ol.source.MapQuest.html" title="API documentation for ol.source.MapQuest">ol.source.MapQuest</a></li>,<li><a href="../apidoc/ol.source.Vector.html" title="API documentation for ol.source.Vector">ol.source.Vector</a></li>,<li><a href="../apidoc/ol.style.Circle.html" title="API documentation for ol.style.Circle">ol.style.Circle</a></li>,<li><a href="../apidoc/ol.style.Fill.html" title="API documentation for ol.style.Fill">ol.style.Fill</a></li>,<li><a href="../apidoc/ol.style.Stroke.html" title="API documentation for ol.style.Stroke">ol.style.Stroke</a></li>,<li><a href="../apidoc/ol.style.Style.html" title="API documentation for ol.style.Style">ol.style.Style</a></li></ul></div>
        </div>
      </div>

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          <a id="copy-button"><i class="fa fa-clipboard"></i> Copy</a>
          <a id="jsfiddle-button"><i class="fa fa-jsfiddle"></i> Edit</a>
        </div>
        <form method="POST" id="jsfiddle-form" target="_blank" action="http://jsfiddle.net/api/post/jquery/1.11.0/">
          <textarea class="hidden" name="js">var wgs84Sphere &#x3D; new ol.Sphere(6378137);

var raster &#x3D; new ol.layer.Tile({
  source: new ol.source.MapQuest({layer: &#x27;sat&#x27;})
});

var source &#x3D; new ol.source.Vector();

var vector &#x3D; new ol.layer.Vector({
  source: source,
  style: new ol.style.Style({
    fill: new ol.style.Fill({
      color: &#x27;rgba(255, 255, 255, 0.2)&#x27;
    }),
    stroke: new ol.style.Stroke({
      color: &#x27;#ffcc33&#x27;,
      width: 2
    }),
    image: new ol.style.Circle({
      radius: 7,
      fill: new ol.style.Fill({
        color: &#x27;#ffcc33&#x27;
      })
    })
  })
});


/**
 * Currently drawn feature.
 * @type {ol.Feature}
 */
var sketch;


/**
 * The help tooltip element.
 * @type {Element}
 */
var helpTooltipElement;


/**
 * Overlay to show the help messages.
 * @type {ol.Overlay}
 */
var helpTooltip;


/**
 * The measure tooltip element.
 * @type {Element}
 */
var measureTooltipElement;


/**
 * Overlay to show the measurement.
 * @type {ol.Overlay}
 */
var measureTooltip;


/**
 * Message to show when the user is drawing a polygon.
 * @type {string}
 */
var continuePolygonMsg &#x3D; &#x27;Click to continue drawing the polygon&#x27;;


/**
 * Message to show when the user is drawing a line.
 * @type {string}
 */
var continueLineMsg &#x3D; &#x27;Click to continue drawing the line&#x27;;


/**
 * Handle pointer move.
 * @param {ol.MapBrowserEvent} evt
 */
var pointerMoveHandler &#x3D; function(evt) {
  if (evt.dragging) {
    return;
  }
  /** @type {string} */
  var helpMsg &#x3D; &#x27;Click to start drawing&#x27;;

  if (sketch) {
    var geom &#x3D; (sketch.getGeometry());
    if (geom instanceof ol.geom.Polygon) {
      helpMsg &#x3D; continuePolygonMsg;
    } else if (geom instanceof ol.geom.LineString) {
      helpMsg &#x3D; continueLineMsg;
    }
  }

  helpTooltipElement.innerHTML &#x3D; helpMsg;
  helpTooltip.setPosition(evt.coordinate);

  $(helpTooltipElement).removeClass(&#x27;hidden&#x27;);
};


var map &#x3D; new ol.Map({
  layers: [raster, vector],
  target: &#x27;map&#x27;,
  view: new ol.View({
    center: [-11000000, 4600000],
    zoom: 15
  })
});

map.on(&#x27;pointermove&#x27;, pointerMoveHandler);

$(map.getViewport()).on(&#x27;mouseout&#x27;, function() {
  $(helpTooltipElement).addClass(&#x27;hidden&#x27;);
});

var typeSelect &#x3D; document.getElementById(&#x27;type&#x27;);
var geodesicCheckbox &#x3D; document.getElementById(&#x27;geodesic&#x27;);

var draw; // global so we can remove it later
function addInteraction() {
  var type &#x3D; (typeSelect.value &#x3D;&#x3D; &#x27;area&#x27; ? &#x27;Polygon&#x27; : &#x27;LineString&#x27;);
  draw &#x3D; new ol.interaction.Draw({
    source: source,
    type: /** @type {ol.geom.GeometryType} */ (type),
    style: new ol.style.Style({
      fill: new ol.style.Fill({
        color: &#x27;rgba(255, 255, 255, 0.2)&#x27;
      }),
      stroke: new ol.style.Stroke({
        color: &#x27;rgba(0, 0, 0, 0.5)&#x27;,
        lineDash: [10, 10],
        width: 2
      }),
      image: new ol.style.Circle({
        radius: 5,
        stroke: new ol.style.Stroke({
          color: &#x27;rgba(0, 0, 0, 0.7)&#x27;
        }),
        fill: new ol.style.Fill({
          color: &#x27;rgba(255, 255, 255, 0.2)&#x27;
        })
      })
    })
  });
  map.addInteraction(draw);

  createMeasureTooltip();
  createHelpTooltip();

  var listener;
  draw.on(&#x27;drawstart&#x27;,
      function(evt) {
        // set sketch
        sketch &#x3D; evt.feature;

        /** @type {ol.Coordinate|undefined} */
        var tooltipCoord &#x3D; evt.coordinate;

        listener &#x3D; sketch.getGeometry().on(&#x27;change&#x27;, function(evt) {
          var geom &#x3D; evt.target;
          var output;
          if (geom instanceof ol.geom.Polygon) {
            output &#x3D; formatArea(/** @type {ol.geom.Polygon} */ (geom));
            tooltipCoord &#x3D; geom.getInteriorPoint().getCoordinates();
          } else if (geom instanceof ol.geom.LineString) {
            output &#x3D; formatLength( /** @type {ol.geom.LineString} */ (geom));
            tooltipCoord &#x3D; geom.getLastCoordinate();
          }
          measureTooltipElement.innerHTML &#x3D; output;
          measureTooltip.setPosition(tooltipCoord);
        });
      }, this);

  draw.on(&#x27;drawend&#x27;,
      function(evt) {
        measureTooltipElement.className &#x3D; &#x27;tooltip tooltip-static&#x27;;
        measureTooltip.setOffset([0, -7]);
        // unset sketch
        sketch &#x3D; null;
        // unset tooltip so that a new one can be created
        measureTooltipElement &#x3D; null;
        createMeasureTooltip();
        ol.Observable.unByKey(listener);
      }, this);
}


/**
 * Creates a new help tooltip
 */
function createHelpTooltip() {
  if (helpTooltipElement) {
    helpTooltipElement.parentNode.removeChild(helpTooltipElement);
  }
  helpTooltipElement &#x3D; document.createElement(&#x27;div&#x27;);
  helpTooltipElement.className &#x3D; &#x27;tooltip hidden&#x27;;
  helpTooltip &#x3D; new ol.Overlay({
    element: helpTooltipElement,
    offset: [15, 0],
    positioning: &#x27;center-left&#x27;
  });
  map.addOverlay(helpTooltip);
}


/**
 * Creates a new measure tooltip
 */
function createMeasureTooltip() {
  if (measureTooltipElement) {
    measureTooltipElement.parentNode.removeChild(measureTooltipElement);
  }
  measureTooltipElement &#x3D; document.createElement(&#x27;div&#x27;);
  measureTooltipElement.className &#x3D; &#x27;tooltip tooltip-measure&#x27;;
  measureTooltip &#x3D; new ol.Overlay({
    element: measureTooltipElement,
    offset: [0, -15],
    positioning: &#x27;bottom-center&#x27;
  });
  map.addOverlay(measureTooltip);
}


/**
 * Let user change the geometry type.
 * @param {Event} e Change event.
 */
typeSelect.onchange &#x3D; function(e) {
  map.removeInteraction(draw);
  addInteraction();
};


/**
 * format length output
 * @param {ol.geom.LineString} line
 * @return {string}
 */
var formatLength &#x3D; function(line) {
  var length;
  if (geodesicCheckbox.checked) {
    var coordinates &#x3D; line.getCoordinates();
    length &#x3D; 0;
    var sourceProj &#x3D; map.getView().getProjection();
    for (var i &#x3D; 0, ii &#x3D; coordinates.length - 1; i &lt; ii; ++i) {
      var c1 &#x3D; ol.proj.transform(coordinates[i], sourceProj, &#x27;EPSG:4326&#x27;);
      var c2 &#x3D; ol.proj.transform(coordinates[i + 1], sourceProj, &#x27;EPSG:4326&#x27;);
      length +&#x3D; wgs84Sphere.haversineDistance(c1, c2);
    }
  } else {
    length &#x3D; Math.round(line.getLength() * 100) / 100;
  }
  var output;
  if (length &gt; 100) {
    output &#x3D; (Math.round(length / 1000 * 100) / 100) +
        &#x27; &#x27; + &#x27;km&#x27;;
  } else {
    output &#x3D; (Math.round(length * 100) / 100) +
        &#x27; &#x27; + &#x27;m&#x27;;
  }
  return output;
};


/**
 * format length output
 * @param {ol.geom.Polygon} polygon
 * @return {string}
 */
var formatArea &#x3D; function(polygon) {
  var area;
  if (geodesicCheckbox.checked) {
    var sourceProj &#x3D; map.getView().getProjection();
    var geom &#x3D; /** @type {ol.geom.Polygon} */(polygon.clone().transform(
        sourceProj, &#x27;EPSG:4326&#x27;));
    var coordinates &#x3D; geom.getLinearRing(0).getCoordinates();
    area &#x3D; Math.abs(wgs84Sphere.geodesicArea(coordinates));
  } else {
    area &#x3D; polygon.getArea();
  }
  var output;
  if (area &gt; 10000) {
    output &#x3D; (Math.round(area / 1000000 * 100) / 100) +
        &#x27; &#x27; + &#x27;km&lt;sup&gt;2&lt;/sup&gt;&#x27;;
  } else {
    output &#x3D; (Math.round(area * 100) / 100) +
        &#x27; &#x27; + &#x27;m&lt;sup&gt;2&lt;/sup&gt;&#x27;;
  }
  return output;
};

addInteraction();
</textarea>
          <textarea class="hidden" name="css">.tooltip {
  position: relative;
  background: rgba(0, 0, 0, 0.5);
  border-radius: 4px;
  color: white;
  padding: 4px 8px;
  opacity: 0.7;
  white-space: nowrap;
}
.tooltip-measure {
  opacity: 1;
  font-weight: bold;
}
.tooltip-static {
  background-color: #ffcc33;
  color: black;
  border: 1px solid white;
}
.tooltip-measure:before,
.tooltip-static:before {
  border-top: 6px solid rgba(0, 0, 0, 0.5);
  border-right: 6px solid transparent;
  border-left: 6px solid transparent;
  content: &quot;&quot;;
  position: absolute;
  bottom: -6px;
  margin-left: -7px;
  left: 50%;
}
.tooltip-static:before {
  border-top-color: #ffcc33;
}</textarea>
          <textarea class="hidden" name="html">&lt;div class&#x3D;&quot;row-fluid&quot;&gt;
  &lt;div class&#x3D;&quot;span12&quot;&gt;
    &lt;div id&#x3D;&quot;map&quot; class&#x3D;&quot;map&quot;&gt;&lt;/div&gt;
  &lt;/div&gt;
&lt;/div&gt;
&lt;form class&#x3D;&quot;form-inline&quot;&gt;
  &lt;label&gt;Geometry type &amp;nbsp;&lt;/label&gt;
    &lt;select id&#x3D;&quot;type&quot;&gt;
      &lt;option value&#x3D;&quot;length&quot;&gt;Length&lt;/option&gt;
      &lt;option value&#x3D;&quot;area&quot;&gt;Area&lt;/option&gt;
    &lt;/select&gt;
    &lt;label class&#x3D;&quot;checkbox&quot;&gt;&lt;input type&#x3D;&quot;checkbox&quot; id&#x3D;&quot;geodesic&quot;/&gt;use geodesic measures&lt;/label&gt;
&lt;/form&gt;
</textarea>
          <input type="hidden" name="wrap" value="l">
          <input type="hidden" name="resources" value="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css,https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js,http://openlayers.org/en/v3.11.1/css/ol.css,http://openlayers.org/en/v3.11.1/build/ol.js">
        </form>
        <pre><code id="example-source" class="language-markup">&lt;!DOCTYPE html&gt;
&lt;html&gt;
&lt;head&gt;
&lt;title&gt;Measure example&lt;/title&gt;
&lt;script src="https://code.jquery.com/jquery-1.11.2.min.js"&gt;&lt;/script&gt;
&lt;link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css"&gt;
&lt;script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"&gt;&lt;/script&gt;
&lt;link rel="stylesheet" href="http://openlayers.org/en/v3.11.1/css/ol.css" type="text/css"&gt;
&lt;script src="http://openlayers.org/en/v3.11.1/build/ol.js"&gt;&lt;/script&gt;

&lt;style&gt;
.tooltip {
  position: relative;
  background: rgba(0, 0, 0, 0.5);
  border-radius: 4px;
  color: white;
  padding: 4px 8px;
  opacity: 0.7;
  white-space: nowrap;
}
.tooltip-measure {
  opacity: 1;
  font-weight: bold;
}
.tooltip-static {
  background-color: #ffcc33;
  color: black;
  border: 1px solid white;
}
.tooltip-measure:before,
.tooltip-static:before {
  border-top: 6px solid rgba(0, 0, 0, 0.5);
  border-right: 6px solid transparent;
  border-left: 6px solid transparent;
  content: &quot;&quot;;
  position: absolute;
  bottom: -6px;
  margin-left: -7px;
  left: 50%;
}
.tooltip-static:before {
  border-top-color: #ffcc33;
}
&lt;/style&gt;
&lt;/head&gt;
&lt;body&gt;
&lt;div class="container-fluid"&gt;

&lt;div class&#x3D;&quot;row-fluid&quot;&gt;
  &lt;div class&#x3D;&quot;span12&quot;&gt;
    &lt;div id&#x3D;&quot;map&quot; class&#x3D;&quot;map&quot;&gt;&lt;/div&gt;
  &lt;/div&gt;
&lt;/div&gt;
&lt;form class&#x3D;&quot;form-inline&quot;&gt;
  &lt;label&gt;Geometry type &amp;nbsp;&lt;/label&gt;
    &lt;select id&#x3D;&quot;type&quot;&gt;
      &lt;option value&#x3D;&quot;length&quot;&gt;Length&lt;/option&gt;
      &lt;option value&#x3D;&quot;area&quot;&gt;Area&lt;/option&gt;
    &lt;/select&gt;
    &lt;label class&#x3D;&quot;checkbox&quot;&gt;&lt;input type&#x3D;&quot;checkbox&quot; id&#x3D;&quot;geodesic&quot;/&gt;use geodesic measures&lt;/label&gt;
&lt;/form&gt;

&lt;/div&gt;
&lt;script&gt;
var wgs84Sphere &#x3D; new ol.Sphere(6378137);

var raster &#x3D; new ol.layer.Tile({
  source: new ol.source.MapQuest({layer: &#x27;sat&#x27;})
});

var source &#x3D; new ol.source.Vector();

var vector &#x3D; new ol.layer.Vector({
  source: source,
  style: new ol.style.Style({
    fill: new ol.style.Fill({
      color: &#x27;rgba(255, 255, 255, 0.2)&#x27;
    }),
    stroke: new ol.style.Stroke({
      color: &#x27;#ffcc33&#x27;,
      width: 2
    }),
    image: new ol.style.Circle({
      radius: 7,
      fill: new ol.style.Fill({
        color: &#x27;#ffcc33&#x27;
      })
    })
  })
});


/**
 * Currently drawn feature.
 * @type {ol.Feature}
 */
var sketch;


/**
 * The help tooltip element.
 * @type {Element}
 */
var helpTooltipElement;


/**
 * Overlay to show the help messages.
 * @type {ol.Overlay}
 */
var helpTooltip;


/**
 * The measure tooltip element.
 * @type {Element}
 */
var measureTooltipElement;


/**
 * Overlay to show the measurement.
 * @type {ol.Overlay}
 */
var measureTooltip;


/**
 * Message to show when the user is drawing a polygon.
 * @type {string}
 */
var continuePolygonMsg &#x3D; &#x27;Click to continue drawing the polygon&#x27;;


/**
 * Message to show when the user is drawing a line.
 * @type {string}
 */
var continueLineMsg &#x3D; &#x27;Click to continue drawing the line&#x27;;


/**
 * Handle pointer move.
 * @param {ol.MapBrowserEvent} evt
 */
var pointerMoveHandler &#x3D; function(evt) {
  if (evt.dragging) {
    return;
  }
  /** @type {string} */
  var helpMsg &#x3D; &#x27;Click to start drawing&#x27;;

  if (sketch) {
    var geom &#x3D; (sketch.getGeometry());
    if (geom instanceof ol.geom.Polygon) {
      helpMsg &#x3D; continuePolygonMsg;
    } else if (geom instanceof ol.geom.LineString) {
      helpMsg &#x3D; continueLineMsg;
    }
  }

  helpTooltipElement.innerHTML &#x3D; helpMsg;
  helpTooltip.setPosition(evt.coordinate);

  $(helpTooltipElement).removeClass(&#x27;hidden&#x27;);
};


var map &#x3D; new ol.Map({
  layers: [raster, vector],
  target: &#x27;map&#x27;,
  view: new ol.View({
    center: [-11000000, 4600000],
    zoom: 15
  })
});

map.on(&#x27;pointermove&#x27;, pointerMoveHandler);

$(map.getViewport()).on(&#x27;mouseout&#x27;, function() {
  $(helpTooltipElement).addClass(&#x27;hidden&#x27;);
});

var typeSelect &#x3D; document.getElementById(&#x27;type&#x27;);
var geodesicCheckbox &#x3D; document.getElementById(&#x27;geodesic&#x27;);

var draw; // global so we can remove it later
function addInteraction() {
  var type &#x3D; (typeSelect.value &#x3D;&#x3D; &#x27;area&#x27; ? &#x27;Polygon&#x27; : &#x27;LineString&#x27;);
  draw &#x3D; new ol.interaction.Draw({
    source: source,
    type: /** @type {ol.geom.GeometryType} */ (type),
    style: new ol.style.Style({
      fill: new ol.style.Fill({
        color: &#x27;rgba(255, 255, 255, 0.2)&#x27;
      }),
      stroke: new ol.style.Stroke({
        color: &#x27;rgba(0, 0, 0, 0.5)&#x27;,
        lineDash: [10, 10],
        width: 2
      }),
      image: new ol.style.Circle({
        radius: 5,
        stroke: new ol.style.Stroke({
          color: &#x27;rgba(0, 0, 0, 0.7)&#x27;
        }),
        fill: new ol.style.Fill({
          color: &#x27;rgba(255, 255, 255, 0.2)&#x27;
        })
      })
    })
  });
  map.addInteraction(draw);

  createMeasureTooltip();
  createHelpTooltip();

  var listener;
  draw.on(&#x27;drawstart&#x27;,
      function(evt) {
        // set sketch
        sketch &#x3D; evt.feature;

        /** @type {ol.Coordinate|undefined} */
        var tooltipCoord &#x3D; evt.coordinate;

        listener &#x3D; sketch.getGeometry().on(&#x27;change&#x27;, function(evt) {
          var geom &#x3D; evt.target;
          var output;
          if (geom instanceof ol.geom.Polygon) {
            output &#x3D; formatArea(/** @type {ol.geom.Polygon} */ (geom));
            tooltipCoord &#x3D; geom.getInteriorPoint().getCoordinates();
          } else if (geom instanceof ol.geom.LineString) {
            output &#x3D; formatLength( /** @type {ol.geom.LineString} */ (geom));
            tooltipCoord &#x3D; geom.getLastCoordinate();
          }
          measureTooltipElement.innerHTML &#x3D; output;
          measureTooltip.setPosition(tooltipCoord);
        });
      }, this);

  draw.on(&#x27;drawend&#x27;,
      function(evt) {
        measureTooltipElement.className &#x3D; &#x27;tooltip tooltip-static&#x27;;
        measureTooltip.setOffset([0, -7]);
        // unset sketch
        sketch &#x3D; null;
        // unset tooltip so that a new one can be created
        measureTooltipElement &#x3D; null;
        createMeasureTooltip();
        ol.Observable.unByKey(listener);
      }, this);
}


/**
 * Creates a new help tooltip
 */
function createHelpTooltip() {
  if (helpTooltipElement) {
    helpTooltipElement.parentNode.removeChild(helpTooltipElement);
  }
  helpTooltipElement &#x3D; document.createElement(&#x27;div&#x27;);
  helpTooltipElement.className &#x3D; &#x27;tooltip hidden&#x27;;
  helpTooltip &#x3D; new ol.Overlay({
    element: helpTooltipElement,
    offset: [15, 0],
    positioning: &#x27;center-left&#x27;
  });
  map.addOverlay(helpTooltip);
}


/**
 * Creates a new measure tooltip
 */
function createMeasureTooltip() {
  if (measureTooltipElement) {
    measureTooltipElement.parentNode.removeChild(measureTooltipElement);
  }
  measureTooltipElement &#x3D; document.createElement(&#x27;div&#x27;);
  measureTooltipElement.className &#x3D; &#x27;tooltip tooltip-measure&#x27;;
  measureTooltip &#x3D; new ol.Overlay({
    element: measureTooltipElement,
    offset: [0, -15],
    positioning: &#x27;bottom-center&#x27;
  });
  map.addOverlay(measureTooltip);
}


/**
 * Let user change the geometry type.
 * @param {Event} e Change event.
 */
typeSelect.onchange &#x3D; function(e) {
  map.removeInteraction(draw);
  addInteraction();
};


/**
 * format length output
 * @param {ol.geom.LineString} line
 * @return {string}
 */
var formatLength &#x3D; function(line) {
  var length;
  if (geodesicCheckbox.checked) {
    var coordinates &#x3D; line.getCoordinates();
    length &#x3D; 0;
    var sourceProj &#x3D; map.getView().getProjection();
    for (var i &#x3D; 0, ii &#x3D; coordinates.length - 1; i &lt; ii; ++i) {
      var c1 &#x3D; ol.proj.transform(coordinates[i], sourceProj, &#x27;EPSG:4326&#x27;);
      var c2 &#x3D; ol.proj.transform(coordinates[i + 1], sourceProj, &#x27;EPSG:4326&#x27;);
      length +&#x3D; wgs84Sphere.haversineDistance(c1, c2);
    }
  } else {
    length &#x3D; Math.round(line.getLength() * 100) / 100;
  }
  var output;
  if (length &gt; 100) {
    output &#x3D; (Math.round(length / 1000 * 100) / 100) +
        &#x27; &#x27; + &#x27;km&#x27;;
  } else {
    output &#x3D; (Math.round(length * 100) / 100) +
        &#x27; &#x27; + &#x27;m&#x27;;
  }
  return output;
};


/**
 * format length output
 * @param {ol.geom.Polygon} polygon
 * @return {string}
 */
var formatArea &#x3D; function(polygon) {
  var area;
  if (geodesicCheckbox.checked) {
    var sourceProj &#x3D; map.getView().getProjection();
    var geom &#x3D; /** @type {ol.geom.Polygon} */(polygon.clone().transform(
        sourceProj, &#x27;EPSG:4326&#x27;));
    var coordinates &#x3D; geom.getLinearRing(0).getCoordinates();
    area &#x3D; Math.abs(wgs84Sphere.geodesicArea(coordinates));
  } else {
    area &#x3D; polygon.getArea();
  }
  var output;
  if (area &gt; 10000) {
    output &#x3D; (Math.round(area / 1000000 * 100) / 100) +
        &#x27; &#x27; + &#x27;km&lt;sup&gt;2&lt;/sup&gt;&#x27;;
  } else {
    output &#x3D; (Math.round(area * 100) / 100) +
        &#x27; &#x27; + &#x27;m&lt;sup&gt;2&lt;/sup&gt;&#x27;;
  }
  return output;
};

addInteraction();

&lt;/script&gt;
&lt;/body&gt;
&lt;/html&gt;</code></pre>
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